now did you have to go to the dealership to have it programed to you car?
No you don't. BUT if you upgrade to the 8 inch, you have to get a new head unit(the one for the 4.3 will not work), new bezel, 8 inch screen, a/c controls and maybe gps/siruis antenna(if your car doesn't have it).
so your main question would be do you want just the 8.4 upgrade(RE2) or you want the 8.4 with nav upgrade(RB5). Me myself I said if i was gonna do it, might as well go big so i got the RB5. If you get a 2011 heads unit, it's plug and play. If you get 2012 and up, you will have to contact the dealer to get a antilock code to activate the unit.
Overall, if you do the factory upgrade you will have anywhere from $800-$1000 in it all. Especially now because more people are doing it so prices are increasing but it is worth it! I literally feel like I have a new car going from that little a** screen to this huge one! It is worth the money and the factory look is sooo clean!